Beam compass



A. ACKRON BEAM COMPASS June 13, 1939.

Filed Aug. 19, 1957 v Fm wLm g INVENTOR. BERT ACKRON.

A BY fig ATTORNEY.

Patented June 13, 1939 UNITED STATES PATENT OFFICE 6 Claims.

This invention relates to a compass and more particularly to an extensible beam compass for draftmens use, although certain features thereof may be employed with equal advantage for other purposes.

It contemplates more especially the provision of an efficient, light, dependable and inexpensive extensible compass for describing circles of large diameter that is beyond the limitations of the ordinary compass now in general use.

Numerous types of compasses have heretofore been proposed for varied purposes, but these are not entirely satisfactory in describing unusually large circles beyond eight to twelve inches in radius. Then, too, beam compasses have heretofore been used wherein rigid wood beams are employed and each compass is supplied with a plurality of beams of different lengths so that i one can be substituted for the other in describing circles of the desired size. Such a device is objectionable for numerous reasons, and it is the purpose of the present invention to provide an improved extensible compass that is graduated so that circles may be described of almost limitless size without resort to extraneous rulers or entailing a great deal of care in setting such to the desired radius prior to describing the circle.

One object of the present invention is to simplify the construction and improve the operation of devices of the character mentioned.

Another object is to provide an improved extensible beam compass that is light, simple, and inexpensive in construction and effective in use.

Still another object is to provide an improved beam compass having calibrations to afford the immediate and accurate setting of the component parts to describe large size circles without entailing any appreciable time in the adjustment thereof.

A further object is to provide a beam compass having increased flexibility for describing circles of predetermined size with means for readily rendering such extensible or collapsible depending upon the requirements of any particular drawing.

A still further object is to provide a beam compass providing a sectional calibrated beam to describe circles of varying size from the smallest to the very largest without entailing any appreciable time, effort or care in the manipulation thereof.

A further object is to provide a beam compass having improved attachments for describing either pencil or ink circles of small or large.

size depending upon the requirements of any particular drawing.

Other objects and advtantages will appear from the following description of an illustrative embodiment of the present invention.

In the drawing:

Figure 1 is a perspective view of a device embodying features of the present invention, parts thereof being broken away to clarify the show- 10 Figure 2 is a fragmentary view of the forward end of the beam shown in Figure 1.

Figure 3 is a fragmentary sectional view taken of the forward end of the tubular member comprising a part of devices embodying features of the present invention.

Figure 4 is a view in elevation of a handle attachment and the fulcrum point for a beam compass involving features of the present invention.

Figure 5 is a fragmentary sectional view in elevation of a compass attachment embodying features of the present invention.

Figure 6 is a perspective view of a part of a sectional beam embodying features of the present invention.

Figure 7 is an end view in elevation of a modified beam compass embodying features of the present invention.

Figure 8 is a perspective view of a still further modified sectional beam constituting a substitute for the section shown in Figure 6.

The structure selected for illustration comprises an elongated tubular metallic member I0, preferably though not essentially of cylindrical configuration to telescopically receive a beam H of substantially thesame length for extensible association therewith. The beam II is preferably a metallic bar of polygonal cross-section, in the preferred formof rectangular cross-section, to provide flat, surfaces for the'permanent impression of various dimensional calibrations l2, l3,v.and such additional scales on the remaining surfaces as commercial practice may dictate.

For that matter the beam Il may be of triangular (Figure 7) or hexagonal (Figure 8) configuration depending upon the required facility to provide different scales to render the use of the relatively telescopic members In and II more effective, speedily adjustable, and accurate in 50 their use to describe circles having a radius within their limits of collapsible and extensible association. It is preferable though not essential to reinforce'the ends of the tubular member II] by swaging or providing end sleeves l4 and I5 that are pressed or otherwise secured thereto in any suitable manner.

To maintain the relatively extensible and collapsible telescopic members Ill and [I in any predetermined adjustable position, a threaded stud 16 engages a correspondingly threaded aperture in the sleeve I5 and tubular member l0 so as to project radially therethrough to engage a surface of the beam. ll, thereby precluding relative rotation between the telescopic members i0 and II as well as retain such in any adjusted position. The threaded stud ['6 may constitute the extremity of a needle pointed rod l'l having an internally threaded knurled engaging coupling sleeve member l8 formed integral with' the needle pointed rod IT.

The needle pointed rod I'I may alternately serve as a fulcrum point or as a handle indisplacing the telescopic members i0-H about its extreme fulcrum l9 having internally threaded coupling sleeve 20 in detachable threaded connection with a threaded stud 2| anchored in and radially projecting from the reinforcing end collar M of the tubular member I I]. It will be noted that the needle pointed fulcrum rod l9 projects from the end collar l4 in a diametrically opposite direction to the alternate handle and fulcrum engaging stud 16. A special handle member 22' (Figure 6) and 22" (Figure 8) may be substituted for the needle pointed rod I1 (Figure 1) to render the manipulation thereof more effective.

In order to describe or circumscribe a circle of any predetermined radius determined from the scales I2 and I3, a pencil or pen or combination point 23 of any suitable construction is detachably associated with the extremity 24 of the beam II, there being a threaded stud 25 extending axially from the extremity 24 of the beam H to receive and secure the confronting plates 26 and 21 of the combination pencil and pen point 23. To secure the confronting plates 26-421 in proper position, a threaded nut 28 engages the stud 25 to hold the plates 262'! with their offset 29 against the correspondingly shaped extremity 24 of the beam H, plate offsets 29 and beam extremity 24 being complemental to each other so as to preclude relative rotation and provide for their retention in alignment with the fulcrum l9 and handle engaging stud I6.

A pencil lead 30' is retained between arcuately curved confronting extremities 3| and 32 of the confronting plates 23 having their opposite confronting extremities 33 and 34 suitably bowed to retain ink therebetween. The bowed extremities 33 and 34 are rendered adjustable to define the line thickness inscribed therewith, and to this end a threaded stud 35 is anchored to the plate 26 to project through the plate 21 for receiving a nut 36 in threaded engagement therewith. It will be noted that the customary pencil or pen point 31 (Figure 8) having a threaded shank 38, may be secured to the beam ll (Fig,- ure 1) or II" (Figure 8) by extending through a vertical aperture 39 (Figure 1) and 39" (Figure 8) for threaded engagement by a pencil point 40 having an internally threaded coupler shank 4| which engages the threaded pen point shank 38 with the beam ll" disposed therebetween.

As shown in Figures 6 and 8, a secondary beam ll and H" may be provided with the pencil and pen point securing aperture 39' and 39 respectively, or the axial stud 25'25" and threadednut 28-28 or both. Then, too, a sleeve or collar l5 and i5" is disposed over each of the secondary beams II" and II" to carry a needle pointed fulcrum l9 and IS" in threaded engagement therewith. A handle member 22' and 22" has a threaded extremity to threadedly engage a correspondingly threaded aperture provided in the collar l5 and [5" in radial alignment with the fulcrum point l9 and I9. The threaded handle extremity projects beyond the interior of the collars l5 and [5" to engage the beams ii and II", thereby precluding relative rotation therebetween. The secondary beams II and II" may be used alone for describing small circles or such may constitute a section for axial end alignment with a corresponding shaped and sizedprimary beam. H. To this end, the secondary beam II is provided with a threaded axial bore 42 (Figure 6) in the free extremity thereof to threadedly engage the stud 25 projecting from the primary beam extremity 24 to render such longer in size and sectional in construction.

In Figure 4 there is shown a detail view of a handle member 22' (see Figure 6) that has a reduced threaded extremity 2| to detachably engage a needle pointed rod I9 having an internally threaded coupler sleeve 20. These parts may be assembled with a beam sleeve l5 disposed therebetween for the specified purpose. In Figure 5 amodified line pen 23' consists of symmetrical confronting plates 26 and 21 punched from a single die to present upstanding confronting extensions 3iand 32 to receive a handle 22 therebetween (Figure 5) or a pencil lead 30 as shown in Figure 1. A threaded stud 25' having a nut 28' retains the plates 26'-2'|' in assembled relation by projecting through the inwardly offset region 29 thereof that registers with the beam extremity 24'. In Figure 7, a triangular beam I I is substituted for the other polygonallyshaped beams described supra. The remaining parts are essentially similar to those described in connection" with the other embodiments which need not be specifically described.

With the arrangement of parts above described, it will be apparent that the tubular elongated member I 0 may desirably have a longitudinal distance of ten inches or any multiple thereof from the center or fulcrum point 19 to the extreme outer edge of its forward reinforcing collar or sleeve [5 so that the graduations l2 and/0r I3 will measure the actual distance from the pencil or pen point 23 as shown on the solid telescopic bar H plus the ten inches or any predetermined multiple thereof defined by the tubular member I U.

Asset forth in Figure 1, the radius defined by the members l'lll| from the fulcrum point [9 to the writing point 23 would be twelve inches; however, this may be varied depending upon the tubular member ID and the calibrations l2 or l3. To procure an extension of the radius defined by the members Ill-l2 without unduly lengtheningthe complemental elements, the sectional or supplemental beam II may be fixed to the extremity of the. primary beam H by having the foremostthreaded end aperture 42 engage a correspondingly threaded stud 25' fixed to the extremity of the beam II. For that matter, the supplemental beam. H may be used independently to describe small circles where it would be too: awkward toresort to the comparatively long members llli-l I to accomplish the intended purpose; This-"isclearly illustrated in Figure 8 and affords the use of the'devic'e for small circles as well as unusually large circles, thereby rendering such unusually flexible in use.-

It will be observed that the beam ll may be of any desired configuration depending upon the dictates of commercial practice and the number of :graduations thatare desired for use in connection therewith. The beam. ll cannot be rotated relative to the tubular member l0 after they are adjusted to their desired position, since the handle or fulcrum shank. IE not only retains the telescopic members Ill-ll in adjusted position but also precludes relative rotation therebetween. Any suitable complemental guide means may be provided between the members l0-Il should commercial practice so dictate.

With the arrangement of parts above described, the pen point 23 or 23' can be readily separated to facilitate cleaning, and such may be used independently of the beam. compass in conjunction with the handle 22' as an ordinary ruling pen. Then, too, the beam H may be removed from the tubular member I0 and the pen 23 disconnected therefrom so that the scales thereon may be used in the form of an ordinary ruler as occasion may require for various purposes in connection with the preparation of drawings.

The pen 23 may be reversed in direction (Figure 1) and a metallic point substituted in lieu of the pencil point 30 thereby rendering the use of the device as dividers for a large range of purposes. For that matter, a sheet metal cutting implement may be substituted for the pen 23 so that circles and arcs can be cut from sheet material such as leather, rubber, paper or thin metallic sheets. This also provides a good layout tool for carpenters, machinists and other technicians who find it necessary to describe arcs and circles in the skilled execution of their work.

A simple and inexpensive combination device has been provided that has a wide range of uses and facilitates the drawing of circles of large diameter which heretofore has been accomplished with large instruments thatrendered their manipulation very difiicult. Various changes may be made in the embodiment of the invention herein specifically described without departing from or sacrificing any of the advantages of the invention or any features thereof, and nothing herein shall be construed as limitations upon the invention, its concept or structural embodiment as to the whole or any part thereof except as defined in the appended claims.

I claim:

1. In a. beam-type compass, the combination with an elongated member, of another elongated member operatively connected to said first named elongated member for longitudinal slidable movement relative to each other, a center point associated with an extremity of one of said elongated members, a line writing point associated with the opposite extremity of the other of said elongated members, and another centerpoint associated with said elongated member intermediate said first named center point and said line writing point for reversible interchangeable use of said center points as handles in describing circles of substantially different diameters.

2. In a beam-type compass, the combination with an elongated tubular member, of another elongated member telescopically disposed within said first named elongated member for longitudinal slidable movement relative to each other, a center point associated with an extremity of one of said elongated members, a line writing point associated with the opposite extremity of the other of said elongated members, and another center point associated with said elongated member intermediate said first 'named'center point and said line writing point for reversible interchangeable use of said center points as handles in describing circles of substantially difierent diameters.

3. In a beam-type compass, the combination with an elongated tubular member, of another elongated member telescopically disposed within said first named elongated member for longitudinal slidable movement relative to each other, a center point detachably associated with an extremity of one of said elongated members, a line writing point detachably associated with the opposite extremity of the other of said elongated members,. and another center point associated with said elongated member intermediate said first named center point and said line writing point for reversible interchangeable use of said center points as handles in describing circles of substantially different diameters.

4. In a beam-type compass, the combination with an elongated member, of another elongated member operatively connected to said first named elongated member for longitudinal slidable movement relative to each other, a center point associated with an extremity of one of said elongated members, a reversible line writing point associated with the opposite extremity of the other of said elongated members, and another center point associated with said first named elongated member intermediate said first named center point and said line writing point, said center points being fixedly spaced along said first named elongated member and extending from opposite sides thereof for reversible interchangeable use of said center points as handles in describing circles of substantially difierent diameters.

5. In a beam type compass, the combination with an elongated tubular member, of another elongated member telescopically disposed within said first named elongated member for longitudinal slidable movement relative to each other, a center point associated with an extremity of one of said elongated members, a line writing point associated with the opposite extremity of the other of said elongated members, and another center point threadedly associated with said first named elongated member intermediate said first named center point and said line writing point, said center points being fixedly spaced along said first named elongated member and extending from opposite sides thereof,

-said last named threadedly associated center point engaging said second named elongated member to maintain said elongated members in adjusted spaced relation for reversible interchangeable use of said center points as handles in describing circles of substantially different diameters.

6. In a beam-type compass, the combination with an elongated tubular member, of another elongated member telescopically disposed within said first named elongated member for longitudinal slidable movement relative to each other, a center point associated with an extremity of one of said elongated members, a line writing point associated with the opposite extremity of the other of said elongated members, a scale inscribed on said second named telescopic elongated member to indicate the radial length between said line writing point and both of said center points, and another center point threaded ly associated with said first named elongated member intermediate said first named center point and said line writing point, said center points vbeing fixedly spaced along said first named elongated member and extending from opposite sides thereof, said last named .threadedly associated center point engaging said second named elongated member to maintain said elongated members in adjusted spaced relation for reversible interchangeable use of said center points as handles in describing circles of substantially different diameters.

ALBERT ACKRON. 

